Fire eliminator for air conveying systems



June 20, 1961 G. e. REED 2,989,348

FIRE ELIMINATOR FOR AIR CONVEYING SYSTEMS Original Filed May 12, 1958 2 Sheets-Sheet 1 FRO M COTTO N O z E GEORGE a. REED I wmvro 5 Z HUEBNER & WORRE'L g ATTORNEYS U1 Z U z June 20, 1961 G. G. REED 2,989,348

FIRE ELIMINATOR FOR AIR CONVEYING SYSTEMS Original Filed May 12, 1958 2 Sheets-Sheet 2 FROM WATER SUPPLY MPRESSED To SPRINKLER AT OUTLET OF FIRE DUCT GEORGE 6. REED INVENT'O/P HUE8NER 8 WORREL A 77'0/PNEVS Patented June 20, 1961 2,989,348 FIRE ELIMINATOR FOR AIR CONVEYING SYSTEMS George G. Reed, 11655 Road 30%, Madera, Calif. Substituted for abandoned application Ser. No. 734,676, May *1'2, 1958. This application Dec. 1, 1959, Ser- No. 860,301

Claims. (Cl. 302-28) The present invention relates to a fire eliminator for use in a system for conveying combustible materials in an air stream and more particularly to the expurgation of burning material from such a system and the quenching thereof.

The present application is a substitute for my prior abandoned application Serial No. 734,676, filed May 12, 1958. Control of fires in cotton gins has been a serious problem. As is well-known in cotton gin operation, cotton is removed from delivery wagons by suction through ducts which carry the cotton in an air stream to driers, boll-breakers, extractors, and eventually to the gin stands. Inasmuch as cotton is a highly combustible material and since it is carried in an air stream through the gin, fires frequently occur in the cotton being conveyed. These fires maybe started through carelessness, as by throwing lighted matches or cigarettes into the cotton; by sparks created by pieces of metallic trash accidentally mixed in with the cotton striking each other or the walls of the conveying ducts; by static electricity; or the like.

However started, such fires are a common occurrence in cotton gins and result in loss of time and money in extinguishing the fires and in making repairs to damaged equipment. In addition to the hazards involved, such fires, if uncontrolled, may cause major financial losses.

It has been known in the past to release a fire extinguishing material into an air stream carrying combustible material 'for the purpose of quenching fires therein. The essence of the subject invention, however, resides in the removal of the burning material from the normal air conveying system in addition to the release of a fire extinguishing agent onto the burning material in a predetermined manner.

Accordingly, it is an object of the present invention to provide a fire eliminator for an air conveying system.

Another object is to purge an air conveying system of burning materials carried in the system.

Another object is to facilitate the control of fires in a cotton ginning system.

Another object is to remove burning cotton from the main conveying duct in a cotton gin.

Another object is to introduce a fire extinguishing agent into an air conveying system for extinguishing fires in the system.

Another object is to provide a duct adapted to convey cotton in an air stream with a plurality of fire outlets connected to an incinerator, or the like, and to divert burning cotton from the duct through the outlets for passage into the incinerator.

Another object is to provide an electro-mechanical control apparatus for operating the cotton divert-ing and fire extinguishing devices described above. I

Another object is to provide an electrical system for energizing and de-energizing the diverting and extinguishing devices in a predetermined manner.

Other objects are to provide a fire eliminator for an air conveying system of the nature described which is simple and economical to make and use, which is dependable in action, and which is adapted for installation on new and existing structures.

These, together with other objects, will become more tfully apparent upon reference to the following description and accompanying drawings.

In the drawings:

FIG. 1 is a fragmentary diagrammatic view of a portion of a cotton ginning system incorporating a fire eliminator embodying the principles of the present invention.

FIG. 2 is a somewhat enlarged fragmentary View of a portion of the structure illustrated in FIG. 1.

FIG. 3 is a diagrammatic view of an electro-mechanical system employed for controlling the apparatus of the subject invention.

Referring more particularly to the drawings, a cotton ginning system is partially illustrated in FIG. 1 and includes an elongated main cotton duct 10 having a predetermined receiving station 11 and a predetermined delivery station 12. The receiving station is adapted for connection to a supply of cotton in a manner well-known but not'specifically illustrated. Actually, the receiving station of the cotton duct usually includes an elongated spout adapted for extension into a wagon of cotton whereupon the cotton is drawn upwardly from the Wagon by pneumatic suction. The main duct includes a plurality of coupling sections 14 and valve housings 15 interconnecting the coupling sections. Each valve housing has an inlet 16, a fire outlet 17, and a main passageway 13 in angular relation to the fire outlet.

A fan 20 is diagrammatically represented as being connected in the coupling section 14 of the duct 10 adjacent to the receiving station 11. The fan is connected so as to create a flow of air in a direction from the receiving station to the delivery station 12, as indicated by the arrow 21. Additionally, a drier-extractor 22, or other ginning equipment, is connected in one of the other coupling sections illustrated. The delivery station 12 of the duct may be regarded as including a gin stand, not shown, as the legend on the drawing indicates. In normal operation of the cotton ginning system, the fan draws cotton from the supply thereof through the main duct into the drier-extractor, and through other ginning equipment, not shown, and eventually to the gin stand.

The subject invention provides an elongated fire duct 26 having an inlet end 27 and a discharge or outlet end 28 in spaced relation to the inlet end. A blower 29 is. connected to the fire duct for mtablishing flow of air from the inlet end to the discharge end in the direction indicated by the arrow 30. Preferably, a suction pump 31 is connected adjacent to the discharge end of the fire duct so as to act in cooperation with the blower for establishing said flow of air. A fire receptacle-33, such as an incinerator, is connected to the discharge end of the fire duct, and a plurality of burning material conductors 34 individually interconnect the fire outlets 17 of the main duct 10 with the fire duct in longitudinally spaced relation therealong.

Fire rejecting valve plates 40 are mounted within the housings 15 by means of binge pins 4 1 for movement between positions -alternately blocking passage of air through the fire outlet 17 and the main passageway 18. In a normal position, each valve'plate is extended transversely of the fire outlet, as shown in FIG. 1, whereby passage of air, and thus cotton carried thereby, are precluded from passage from the main duct through the conductors 34 into the fire duct 26. In anemergency position, each valve plate is extended transversely of themain passageway 18 to prevent flow of cotton between the coupling sections 14 of the mainlductwhile traveling from the receiving v, station 11 to the delivery station 12. Conversely, of course, when cotton and air are precluded from traveling in" either the fire outlet or the main passageway, they are permitted to pass in the unblocked fire outlet or passageway. It is to be notedthat when the valve plates are in their emergency positions, communication is established between the receiving station of the main duct and the fire receptacle 33.

A quadrant 42 is rigidly mounted internally on each of the valve housings 1S and includes an arcuate slot 43 in registration with a corresponding slot in the housing. A control arm 44 is connected to each valve plate 40 for extension outwardly of the slot in its respective housing and through the slot of the associated quadrant. The valve housings and associated valve plates constitute fire control valves 46.

A pneumatic control ram 50, best seen in FIG. 3, pro vides a cylinder 51 having an inner base 52 and an outer end 53, a piston 54 reciprocal in the cylinder, and an elongated piston rod 55 connected to the piston and extended axially outwardly of the cylinder. The base provides a chamber 56, an outer end passage 58, a base passage 59, a base exhaust 60, and an outer end exhaust 61. An elongated conductor 63 pneumatically connects the outer end 53 of the cylinder to the outer end passage 58. A valve member 65 provides a head 66 slidable on the base within the chamber and over the passages 58 and 59 and the exhausts 60 and 61. The head has compartments 67 disposed toward the base and an elongated stem 68 extended outwardly of the chamber. The passages and exhausts in the base and the valve member constitute a ram control valve, generally indicated by the numeral 70. The valve member is shown in a neutral position in FIG. 3 but is slidable in opposite directions therefrom into a ram extend position in which one of the compartments provides pneumatic communication between the conductor 63 and the outer end exhaust 61, and in which air communication is established between the chamber and the base passage 59. In a ram retract position of the valve member, the chamber communicates with the outer end passage and the base exhaust and the base passage are connected through the other one of the compartments 67.

Also integrally connected with the ram 50 and the valve 70 is a double acting solenoid 75 including an outer cylindrical casing 76 providing an outlet 77 communicating with the chamber and an inlet 78. Extend and retract coils 79 and 80 are positioned axially in opposite ends of the casing, and inner magnetically permeable casings 81 surround the coils. An armature 83 includes a central transverse cylinder head 84 having an annular groove 85 in registration with the inlet and outlet of the casing, a central fractionally spherical socket 86, and a radial passageway 87 providing communication between the socket and the groove. A ball 88 is loosely mounted in the socket for axial movement between positions closing or opening the mouths of the socket and opposite ends thereof. The armature also has oppositely extended tubular ram extending and retracting portions 90 and 91, these portions being respectively in circumscribing relation to the extend and retract coils 79 and 80 and the casings 81. Upon energization of the extend coil, the valve member 65 is moved into its ram extending position and upon energization of the retract coil, the valve member is moved into its ram retracting position.

A tank 96 of compressed air is provided, and a pneumatic conductor 97 interconnects the tank and the inlet 78 of the solenoid casing 76. It is also to be noted that the armature S3 is self-centering when the coils 79 and 80 are de-energized. The specific manner in which the ram 50 is controlled by the valve 70 and the solenoid 75 is specifically described in the United States patent to Bellows No. 2,641,229 and accordingly, is not described in any further detail herein. It is to be noted, however, in FIG. 2, that the cylinder 51 is pivotally connected to the main cotton duct by means of a bracket 100, and the piston rod 55 is pivotally connected to the control arm 44 so that upon extension of the ram, the valve plate 40 is moved into normal position, as illustrated in FIG. I, and upon retraction of the ram, the valve plate is moved into its emergency position, as illustrated in FIG. 2. With reference to FIGS. 1 and 2, a plurality of tanks containing a fire extinguishing agent such as liquid carbon dioxide under pressure, are provided each having an outlet conduit 106 connected to the main duct 10 immediately in advance of the valves 46. Considering one of these tanks, a fire extinguishing valve 107 is connected in the outlet conduit 106 and includes a housing 108 having inlet and outlet ports 109 and 110, a valve member 11.1 mounted in the housing for movement between a closed position blocking flow of the extinguishing agent from the tank, as shown in FIG. 3, and an open position providing communication between the inlet and outlet ports for enabling passage of fire extinguishing material through the outlet conduit into the main duct. A stern 112 is connected to the valve member for extension outwardly of the housing, and a coiled compression spring 113 encircles the stem and has opposite ends bearing against the valve member and the housing for yieldably urging the valve member into its closed position. It is to be understood that the extinguishing agent is under pressure in the tank so that upon opening of the control valve 107, it is automatically ejected from the tank.

For controlling opening and closing of the valve 107, a fire extinguishing solenoid 115 is provided having an electrical coil 116 and an armature 117 connected to the stem 112. Upon energization of the solenoid, the

valve is opened and upon de-energization of the solenoid,

the valve is allowed to close under the urgence of the spring 113.

Also, a water valve 120 is provided including a housing 121 having an outlet 122 and an inlet 123 respectively connected to a sprinkler, not shown, but preferably located adjacent to the discharge end 28 of the fire duct 26 and to a source of water, not shown, under pressure. Parenthetically, it is to be noted that the sprinkler is preferably used whenever a fire receptacle 33 or incinerator is not employed so as to spray quenching water onto the burning cotton as it emerges from the fire duct. The valve 120 provides a valve member 125, an elongated stem 126, and a coiled compression spring 127 urging the valve member into a position blocking flow of water from the inlet to the outlet. An electrical water control solenoid 129 includes a coil 130 an an armature 131 connected to the water valve stem 126 so that upon energization of the coil, the valve member is retracted to allow flow of water from the inlet to the outlet and to spray water from the sprinkler.

Considering the electrical system illustrated in FIG. 3, a plurality of unit relays 135 are provided each including a coil 136 and a pair of normally open contacts 137 adapted for closing upon energization of their respective coils.

Further, a plurality of timing relays 140 are provided each including a coil 141, a pair of normally open contacts 142, and a timer 143 having mechanical connection to the movable contact of its respective pair of contacts. Relays of this type are well-known and are not therefore described in minute detail. It is to be noted, however, that upon energization of any one of the coils 14, its respective contacts close and thereupon trigger the timer which, after a predetermined interval, reopens the contacts. The usual time intervals are adjustable between a few seconds and approximately three minutes.

Further, a plurality of disabling relays 146 are provided each including a coil 147 and a pair of contacts 148.

The electrical system also includes a source of voltage indicated by the numeral and having leads 156 and 157 connected thereto. A master control relay 159 includes a coil 160 connected in electrical series circuit with a normally open master control on switch 161 across the source of voltage. The master relay has normally open holding contacts 163, normally closed ram extending contacts 164, and normally open ram retracting and extinguisher valve control contacts 165 and 166,

respectively. A normally closed master control 01f switch 168 interconnects the lead 157 to the holding contacts. It is to be noted that the on and ofi switches are of the push button momentary contact type being normally urged into their respective open or closed positions, as diagrammatically indicated in FIG. 3.

The disabling relay coils 147 are individually connected in electrical series circuit with the ram extend, ram retract, and valve control contacts 164, 165, and 166 and each such series combination is connected across the source of voltage 155. Further, the timing relay coils 141 are individually connected in electrical series circuit with the contacts 148 of the disabling relays 146 and these series combinations are individually connected in parallel with the disabling relay coils 147. Still further, the unit relay coils 136 are individually connected in electrical series circuit with the timing relay contacts 142 and these combinations of series circuits are also connected in parallel across the disabling relay coils 147.

The solenoid extend coil 79 is connected in series circuit with the unit relay contacts 137 associated with the ram extend contacts 164 and this series combination is connected in parallel with its respective unit relay coil 136. The retract coil 80 of the solenoid 75 is similarly connected to an associated unit relay 135. Further. the fire extinguisher solenoid 115 is also similarly connected to the remaining unit relay.

The water control solenoid 129 has one end connected to the lead 156 and the other end electrically connected to the movable contact of the ram retract contacts 165. In addition, a green warning lamp 175 electrically interconnects the lead 156 and the movable contact of the ram extend contacts 164, and a red warning lamp 176 is electrically connected in parallel with the water control solenoid 129.

Operation The operation of the described embodiment of the subject invention is believed to be evident and is briefly summarized at this point.

Under normal conditions of operation of the cotton ginning system, the apparatus is in the condition shown in FIGS. 1 and 3. More specifically, the master control relay 159 is de-energized so that the ram extend contacts 164 are closed. This establishes a complete circuit from the source of voltage 155 through the green lamp 175 so that the latter is on and indicates to all that the system is in normal working condition. Further, the rams 50 are all in their extended positions, as shown in FIG. 1, so that the main passageways 18 of the valve 46 are open throughout the main duct 10. Additionally, the fire extinguisher and water valves 107 and 120 are closed.

' The 'fan, the blower, and pump 20, 29 and 31 are all energized to create the streams of air indicated by arrows 21 and 30 in the main and fire ducts and 26. Cotton is then drawn into the main duct in a conventional manner and carried therethrough in the air stream. Cotton passes through the main passageways 18, the drier and extracting equipment 22, and other cotton ginning equipment not shown, and eventually is delivered to the gin stands, not shown.

The eliminating equipment of the present invention is brought to play if a fire originates in the main duct '10 or any other part of the cotton ginning system in communication with the main duct. As previously explained, the highly combustible cotton is very conducive to initiation of fires. If a fire is detected by smell or sight, an operator pushes the master control on switch -161 to close this switch momentarily. In considering the manner in which the electrical system illustrated in FIG. 3 operates the valve plates 40, it is to be understood that each such valve plate and fire extinguishing tank 105 has an electrical system corresponding to that shown in FIG. 3. Obviously all of these plates 50 operate simultaneously by connecting their respective electrical systems in parallel. Also, the valve plates could be selectively operated in dividually, or sequentially. Inasmuch as the operation of any one of the valve plates by its respective system is the same, only one will be considered. Accordingly, 'ref-' erence will be made to the valve plate associated with the valve 46 located between the fan 20 and the drier-extrac tor 22 in the main duct 10.

Further considering the action of the master relay 159 when energized by closing the on switch 161, the holding contacts 163 close to complete a circuit through the coil 160 and the ofi button 168 to maintain the coil in energized condition. Further, the ram extend contacts 164 open and the ram retract contacts close. This energizes the timing coil 141 to close the timing contacts 142 in the ram retract circuit. This supplies voltage to the unit coil 136 connected to the ram retract coil thereby closing the unit contacts 137 and energizing the ram retract coil. Simultaneous with energization of the timing coil, the disabling coil 147 in the ram retract circuit is energized to open its contact 148 and to de-energize the timing coil immediately after energization thereof and to preclude further energization of the timing coil until the circuit to the master control relay coil is broken by pushing the off button 168.

The ram retract coil 80, through the armature 83, moves the valve member 65 into its ram retract position whereby the ram 50 is retracted and the valve plate 40 is moved in its emergency position, as shown in FIG. 2. Shortly after the valve plate is so moved, the timer 143 in the ram retract circuit opens its associated contacts 142- whereby the unit coil 136 and ram retract coil 30 are de-energized and whereby the armature 83 returns to neutral position. Air is captured in the cylinder 51 of the ram '50, however, so that the ram remains in retracted position. It is desirable to allow the armature to neutralize in order to prevent release of air from the tank 96 and also in order to minimize total current flow in the armature and coil 79 and 83.

With the valve plates 40 in emergency position, cotton is diverted from the main ducts 10 through the conductors 34 and into the fire duct 26 where it is carried in the air stream therein into the incinerator 33. When the valve plates are in their emergency positions, the source of supply of cotton is cut off so that no more cotton is drawn into the duct 10.

Further considering the electrical circuit operation, the water valve control solenoid 29 is energized through the closed ram retract contacts to open the water valve 120 so that water is sprayed onto the burning cotton as it is discharged from the discharge end 28 of the fire duct 26.:

It is to be noted, however, that ordinarily the water sprinkling system is not employed when an incinerator 33 is provided at the discharge end of the fire duct. Although boh of these units could be utilized at the same time, they are preferably alternatively employable.

Further, the fire extinguisher control valve 107 is opened by the valve control contact 166. Inasmuch as the fire extinguisher control circuit includes a timing relay 140, the valve control solenoid 115 is de-energized after a predetermined period of energization, all depending upon the timer 143 in the extinguishing circuit. Momentary opening of the valves gives adequate release of the fire extinguishing agent, such as carbon dioxide, to saturate the sections of the ducts 10 and 26 adjacent to their respective extinguishing tanks 105. In this manner the tanks 105 can be used for an entire ginning season rather than being completely drained during each fire occurrence. The extinguishing agent is ejected into the main duct and in advance of the valve 46. After the valves are in their emergency positions, the extinguishing agent is blown in the air stream along with burning cotton into the fire duct where it aids in extinguishing the fire before reaching and after entering the incinerator 33.

It is also noted that when the on button 161 is closed, the green lamp is de-energized by the open ram ex 7 tend contacts 164 whereas the red lamp 176 is energized through the closed ram retract contacts 165.

After the burning material has been completely purged from the cotton duct 10 and the fire is under control, an operator pushes the off button 168 to Open the holding circuit to the coil thereby to de-energize the master control relay 151. Opening of the ram retract contacts 165 and the valve control contacts 166 has no direct effect on the ram retract coil 80 or the solenoid 115 inasmuch as each of these coils was previously deenergized by opening of their respective timing contacts 142. However, in opening these contacts 164 and 165, the disabling coils 147 in their respective circuits are deenergized to return the disabling contacts 148 in closed position whereby the circuits are preconditioned for subsequent cycles of operation. The ram extend contacts 164 return to closed position whereby the ram extend circuit is placed into operation to energize the ram extend coil 79 and to cause the control ram 59 to move to extended position whereby the valve plate 49 associated with such ram is returned to its normal position in blocking relation to the fire outlets 17. After a predetermined time interval, the extend coil is de-energized and the valve member 65 returns to neutral position whereby the ram is held in extended position but the air supply from the tank 96 is shut ofi. The red lamp 176 is de-energized and the green lamp 175 is energized to show that the system is again working in a normal manner.

It is to be emphasized that the illustration in FIG. 1 is diagrammatic. The valves 46 and the connection established by conductors 34 from the main duct to the fire duct can be located at any point throughout the cotton ginning system. The principle of operation of the device remains the same regardless of its particular location.

The apparatus of the subject invention has been employed in cotton ginning systems with a considerable measure of success. This has been demonstrated, for example, in one gin operation employing a crew of six men and having an average of sixty-seven hours of shutdown time per year for two consecutive ginning seasons as the result of fires. This gin installed the subject fire eliminating system and reduced their shutdown time due to fires to approximately three hours. In this particular gin, over eleven thousand bales of cotton were ginned during which time twenty fires occurred. However, because of the use of the subject invention, the fires were not allowed to progress to the point where smoke developed in the building nor was there any damage to any of the regular cotton ginning equipment, such as brushes, feeders, gin stands, and the like. It will be evident, therefore, that the apparatus of the subject invention is highly effective for accomplishing its intended purposm. It is significant that the invention provides for the removal of burning material from a normal conveying line into an auxiliary line where the burning materal is delivered to a receptacle such as an incinerator. Quenching of the fires is quickly effected by the introduction simultaneously with the removal of a quantity of fire extinguishing material and/or by spraying water on the fire.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment. it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an apparatus for conveying combustible materials in an air stream including an elongated main duct having predetermined longitudinally spaced material receiving and material delivery stations, and a fire outlet intermediate said stations; means for supplying combustible materials to the main duct at said material receiving station; an elongated fire duct; a material conductor connecting the fire outlet to the fire duct; air pump means connected in pneumatic communication with the main and fire ducts establishing a pressure differential between said receiving station and said fire duct and between said receiving and delivery stations tending to create flow of air from the receiving station to the fire duct and to the delivery station to carry such combustible materials therewith; controllable means mounted in the main duct and movable between positions blocking the main duct and blocking the fire outlet for allowing flow of materials in the main duct only or for diverting the fiow of combustible materials from the main duct and through the tire outlet into the fire duct; a source of fiowable fire extinguishing agent; and valve means interconnecting the source of fire extinguishing agent and the main duct.

2. In an apparatus for conveying combustible materials in an air stream including an elongated main duct having predetermined longitudinally spaced material receiving and material delivery stations, and a fire outlet intermediate said stations; means for supplying combustible materials to the main duct at said material receiving station; an elongated fire duct; 9. material conductor connecting the fire outlet to the fire duct; a main blower connected to the main duct for creating an air stream in the main duct flowing from the receiving station to the delivery station thereby to carry combustible materials from the receiving station past the fire outlet to the delivery station; an auxiliary blower connected to the fire duct causing air to flow in a predetermined direction in the fire duct; controllable means mounted in the main duct and movable between positions blocking the main duct and blocking the fire outlet for allowing flow of materials in the main duct only or for diverting the fiow of combustible materials from the main duct and through the fire outlet into the fire duct; a tank containing a fiowable fire extinguishing agent and having an outlet; conducting means including a valve having open and closed positions and interconnecting the outlet and one of the ducts for releasing such agent into such duct upon opening of the valve; and means connected to the valve for opening and closing the valve.

3. The apparatus of claim 2 wherein the valve includes a valve member movable between said open and closed positions and a spring yieldably urging the valve member into closed position, wherein said valve opening and closing means includes an electromagnetic means connected to said valve member for moving it into open position; and an electrical circuit including a source of electrical voltage connected to the electromagnetic means for energization thereof thereby to move the valve member into open position, said circuit further including means for de-energizing the electromagnetic means within a predetermined time interval after the valve member is moved to its open position to allow the spring to return the valve member to its closed position after a predetermined charge of said flowable fire extinguishing agent has been released.

4. In an apparatus for conveying combustible material by air and adapted to control the flow of such combustible material when burning, a fire receptacle; an elongated main duct having predetermined longitudinally spaced material receiving and material delivery stations and a fire control valve intermediate said stations including a housing providing a main passageway interconnecting said material receiving and delivery stations, and a fire outlet communicating with the receiving station; material conducting means interconnecting the fire outlet and the fire receptacle; a pump connected to the main duct estab lishing a pressure difierential between said material receiving and delivery stations to enable a fiow of air from said receiving station to said delivery station to convey such material therewith; means connected to the receptacle establishing a pressure differential between said receiving station and the fire receptacle for enabling a flow of air from the receiving station to the receptacle, the valve including a valve member mounted in the housing for pivotal movement between normal and emergency positions transversely of the fire outlet and the main passageway, respectively, for alternately blocking flow of air from the receiving station to the fire receptacle and to the delivery station, a source of flowable fire extinguishing agent; and valve means interconnecting said source of extinguishing agent and the main duct in advance of the pivotal valve member.

5. In an apparatus for conveying combustible material by air and adapted to control the flow of such combustible material when burning, a fire receptacle; an elongated main duct having predetermined longitudinally spaced material receiving and material delivery stations and a fire control valve intermediate said stations including a housing providing a main passageway interconnecting said material receiving and delivery stations, and a fire outlet communicating with the receiving station; an elongated fire duct having a discharge end connected to the receptacle and an oppositely extended end; a burning material conductor interconnecting the fire duct and said fire outlet; an air pumpconnected to the main duct establishing a pressure diiferential between said material receiving and delivery stations to enable a flow of air from said receiving station to said delivery station to convey such material therewith; an air pump connected to the fire duct establishing a pressure difierential be-' tween said receiving station and the fire receptacle for enabling a flow of air from the receiving station to the re ceiving station to the delivery station; a tank containing a fiowable fire extinguishing agent and having an outlet; and conducting means including a valve having open and closed positions and interconnecting the outlet and the main duct between said material receiving station and the fire control valve for releasing such agent into the 20 main duct upon opening of the valve.

References Cited in the file of this patent UNITED STATES PATENTS Kinyon May 10, 1932 

